Method for enhancing lithographic imaging of isolated and semi-isolated features

摘要

The present invention relates to photolithography methods for enhancing lithographic imaging of isolated and semi-isolated features. A first layer of a first photoresist is formed over a substrate. A second layer of a second photoresist is formed over the first layer. The second photoresist includes a polymer containing an absorbing moiety. The second layer is exposed through a first patterned mask and developed to form a first relief image. The first relief image and the first layer are exposed through a second patterned mask. One of the first and the second patterned masks includes a dense pattern, while the other includes an isolated or a semi-isolated pattern. The first relief image and base soluble regions of the first layer are removed to form a second relief image with an isolated or a semi-isolated pattern. The second layer can also be bleachable upon exposure and bake in the present invention.